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Water, energy, and food, which are closely related to human beings, have been proposed by the Sustainable Development Goals, and there are closely related but contradictory relationships among the three. As one of China's main grain-producing regions, the North China Plain (NCP) with dominant grain-oriented cropping system is faced with severe challenges for agricultural sustainable development, such as water and energy shortages, as well as grain safeguard. In this study, a "TKL-WEFN" model combining Tapio decoupling, Kaya, and LMDI was used to evaluate the synergistic relationship from the water-energy-food (WEF) and determine the key drivers taking Wuqiao County in the NCP as a case. The results showed as follows: the synergistic relationship between water-food, as well as energy-food, showed a "M" shaped fluctuation trend from 2009 to 2018 in Wuqiao County. The best performance was achieved in 2011 and 2016, with the state of high yield and low resource consumption. Food increased by 9.43% and 3.52%, while water resources decreased by 5.95% and 8.91%, and energy decreased by 5.36% and 2.15% in 2011 and 2016, respectively. The changes in water consumption for irrigation and fossil energy consumption per unit area of maize and cotton, as well as the adjustment of planting structure, are the main factors affecting the sustainability of crop systems from 2009 to 2018. Water-saving irrigation, no-tillage, and cropping system transformation can improve resources supply and demand, saving 4.61%–50.27% (with an average of 19.47%) of water consumption and 1.91%–13.08% (with an average of 6.45%) of energy consumption by scenarios analysis. Therefore, changing grain-oriented cropping system while maintaining food security and developing water-saving irrigation technology can accelerate the realization of green agriculture. [Display omitted] • Water, energy shortage, and food security are the challenges in North China Plain. • Water-food and energy-food showed a wave trend in 2009–2018 of Wuqiao County. • The high state was 2011 and 2016, with high yield and low resource consumption. • Water-saving irrigation and cropping system change can be considered in study area. [ABSTRACT FROM AUTHOR]

Intercropping of maize and soybean has proven to be a sustainable cropping system all over the world. In recent years, as imports of maize and soybean have increased, the Chinese government has strongly promoted the maize -soybeans intercropping to prevent a decline in maize production and to obtain an extra soybean harvest. It is not clear what the coupling relationship is between the intercropping model and the change in yield of maize and soybean across China. The research searched for articles that fulfilled the criteria related to maize-soybean intercropping in China since 2000. It investigated the yield change through meta-analysis, and analyzed the allocation path of yield increase based on the field configuration level using single factor analysis, multilevel model analysis and random forest analysis. Compared to monoculture, the total yield of intercropping maize and soybean increased by approximately 12%, while the equivalent yield decreased by 8% and 40%, respectively. The proportion of maize area was crucial for the maize intercrop yield. The shading effect of maize on soybean was a key factor in soybean yield reduction. Increasing the distance between the maize and soybean strips lead to an elevation of soybean intercropping yields without compromising maize yield or the total yield. Huang-Huai-Hai Plain Summer Sowing region and Southwest Mountain region were more suitable for promotion. The yield of intercropping was beneficial in this suitable integrated region when the soybean strip width did not exceed 78 cm (soybean row spacing ≤3) and the distance between the maize and soybean strips ≥ 77 cm. Maize-soybean intercropping had great potential for yield improvement, the overall LER was 1.6. In the Huang-Huai-Hai Plain Summer Sowing and Southwest Mountain regions, the yield-advantaged field configurations were: (soybean strip-width ≤61 cm or soybean rows ≤3, distance between strips ≥65 cm) and (soybean strip-width ≤76 cm or soybean rows ≤3, distance between strips ≥73 cm), respectively. Each plantation regions still need to select the optimal distance based on the local farming facilities and traditional farming habits. The research demonstrates the yield changes of maize-soybean intercropping in China, providing a methodology with certain reference value for intercropping yield improvement based on field configuration level. [ABSTRACT FROM AUTHOR]